1. Field of the Invention
The present invention is related to a minute pressure control system, wherein either constant positive pressure or constant negative pressure is switched on and off prior to being combined together.
2. Description of the Prior Art
A pressure control system for controlling the pressure of an object, ranging from a negative pressure to a positive pressure, is known in the art. It is a well-known art in this system that either a constant positive pressure or a constnt negative pressure is alternately applied to the controllable object in response to the deviation between a preset pressure and an actual pressure. Therefore, a specific feedback loop therefor is needed, causing the system to be complicated.